Being in Belgium in November for a truck show may or may not be your cup of tea/mug of Java, but Mercedes is at least doing its best to make the "Trailer 2011" exhibition interesting. The truck design world moves at a glacial pace compared to the consumer automobile business, and new models have to provide serious and significant commercial improvements if they are to be accepted by the trucking fraternity. Coming off the back of the well-received launch of its new Actros heavyweight tractor unit, Mercedes brought along a trailer concept design that aims to match and extend the significant commercial and environmental advantages of that unit. It looks cool, too.

There's no getting around the fact that trucks are big square boxes that take a lot of energy to plow through the air. The turbulence you feel when overtaking one on the highway is ample evidence of that.

Mercedes has managed to reduce the frontal wind resistance of the Actros tractor unit by 15 percent, through 2,600 hours of wind tunnel testing. The results can be seen clearly on the front face of the unit, which sports a number of subtle winglets, a plate, and channels to control airflow - the influence of all those millions spent on Formula 1 aero research, no doubt.

The logical next step is clearly to apply the same rigorous wind-tunnel work to the trailer half of the equation, and that's exactly what Mercedes has done. The interior dimensions of the trailer have to be maintained, of course, so a front air dam reduces the distance between tractor and trailer. The application of a number of precisely-calculated curved panels to the outside and underneath of the trailer channel air to a striking rear diffuser. In addition, there is a 400-mm (15.75-inch) extension to the rear in the form of a "boat-tail," that reportedly brings extensive aerodynamic benefits.

In total, Mercedes claims an additional 18 percent wind resistance reduction in the tractor-trailer combo, which should equate to a five percent reduction in fuel use. For the average year of a busy trailer, that represents 2,000 liters (530 US gallons) of fuel and an astonishing 5 tons (4.5 tonnes) of CO2.

The trailer is still a concept at this stage, since the extension at the rear will require a change in legislation. The reported benefits are so significant, however, that this may be achieved in due course.

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